The second season of the American sitcom The Big Bang Theory aired on CBS from September 22, 2008 to May 11, 2009. A DVD consisting of all 23 episodes of the season was released on September 15, 2009, and a Blu-ray version was reissued on July 10, 2012, with remastered surround sound audio, whereas the DVD version only had stereo. Jim Parsons submitted the episode "The Bath Item Gift Hypothesis" for consideration due to his nomination for the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series at the 61st Primetime Emmy Awards. In 2009, TV Guide ranked the episode #60 on its list for the 100 Greatest Episodes. Christine Baranski submitted the episode "The Maternal Capacitance" for consideration due to her nomination for the Primetime Emmy Award for Outstanding Guest Actress in a Comedy Series at the 61st Primetime Emmy Awards. Cast Main cast Johnny Galecki as Dr. Leonard Hofstadter Jim Parsons as Dr. Sheldon Cooper Kaley Cuoco as Penny Simon Helberg as Howard Wolowitz Kunal Nayyar as Dr. Rajesh "Raj" Koothrappali Sara Gilbert as Leslie Winkle Recurring cast Carol Ann Susi as Mrs. Wolowitz Mark Harelik as Dr. Eric Gablehauser Brian George as Dr. V.M. Koothrappali Alice Amter as Mrs. Koothrappali John Ross Bowie as Dr. Barry Kripke Sara Rue as Dr. Stephanie Barnett Christine Baranski as Dr. Beverly Hofstadter Kevin Sussman as Stuart Bloom Brian Patrick Wade as Kurt Guest cast Travis Schuldt as Eric Charlie Sheen as himself Octavia Spencer as DMV employee Riki Lindhome as Ramona Nowitzki Lio Tipton as themself Emily Happe as Kathy O'Brien Samantha Potter as herself Michael Trucco as Dr. David Underhill Summer Glau as herself George Smoot as himself Valerie Azlynn as Alicia Jodi Lyn O'Keefe as Mikayla Episodes <onlyinclude> {{Episode table |background = #02A9A3 |overall = 5 |season = 6 |title = 19 |director = 11 |writer = 31 |airdate = 11 |prodcode = 7 |country = U.S. |viewers = 10 |episodes = {{Episode list/sublist|The Big Bang Theory (season 2) |EpisodeNumber = 39 |EpisodeNumber2 = 22 |Title = The Classified Materials Turbulence |DirectedBy = Mark Cendrowski |WrittenBy = |OriginalAirDate = |ProdCode = 3T7373 |Viewers = 9.25 |ShortSummary = Howard celebrates the launch of his latest invention, a zero-gravity human-waste disposal system (a toilet) to be used in the ISS, by buying all of his friends new comic books. However, later Howard discovers he made a mistake that